/*
 * Copyright (C) the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.derquinse.common.reflect;

import static com.google.common.base.Preconditions.checkArgument;

import java.lang.reflect.Type;

import com.google.common.reflect.TypeToken;

/**
 * Base class for classes that make reference to themselves' types.
 * @author Andres Rodriguez
 * @param <T> This type.
 */
public abstract class This<T extends This<T>> {
	/**
	 * Constructor.
	 * @throws IllegalArgumentException if the type argument is not the same (raw type) as the actual
	 *           class.
	 */
	protected This() {
		final Class<?> thisClass = getClass();
		@SuppressWarnings("serial")
		final TypeToken<T> token = new TypeToken<T>(thisClass) {};
		Type raw = token.getRawType();
		checkArgument(thisClass.equals(raw));
	}

	/**
	 * Returns the "this" value.
	 * @return This object.
	 */
	@SuppressWarnings("unchecked")
	public final T thisValue() {
		return (T) this;
	}
}
